The invention relates to a method of producing aryl silanes. More particularly, this invention relates to a method of effecting reaction between a silane of the formula EQU HSiR.sub.3 (I)
and a compound of 6 to 30 carbon atoms having an aromatic nucleus (Ar) and at least one monovalent radical selected from the class consisting of halogen (X) and substituted carbonyl groups of the formula ##STR1## in the presence of an effective amount of transition metal catalyst at a temperature in the range of 150.degree. to 200.degree. C., where R, Ar, Y and X are more particularly defined below.
Aryl silanes are typically utilized as starting materials in the production of aryl-siloxane resins. Prior to this invention aryl silanes were produced by reacting elemental silicon and chlorobenzene at a temperature of about 400.degree. C. in the presence of an effective amount of copper or silver catalyst. The process is disadvantageous in that a significant amount of polychlorinated biphenyls (PCBs) are coproduced. In addition, the high temperature necessary to facilitate reaction requires the use of complex equipment that operates under pressure. The high reaction temperature also places a high energy demand on obtaining the desired product.
An alternative method of producing aryl silanes without producing PCBs is disclosed by Barry in U.S. Pat. No. 2,572,302 and in Advances in Chem. Series 23 (1959) 246. In this process benzene is reacted with chloroorganosilanes in the presence of boron trichloride at about 300.degree. C. Drawbacks in utilizing this process are (1) the expense of maintaining high reaction temperatures and providing the complex equipment necessary to maintain the reactants at such relatively high temperatures and (2) the danger in volatilizing benzene, a highly toxic compound, at temperatures near 300.degree. C.
The present invention overcomes the disadvantage of producing PCBs, does not require the use of temperatures above 200.degree. C. and does not require the use of starting materials, as toxic as benzene.